This preprint develops a domain-guarded semantic framework for null-structural markers. The framework distinguishes structural inapplicability from falsehood by replacing total Has-style predicates with a DomHas/HasVal discipline, formalizes relative eliminability through translation classes and conservativity levels, and introduces a proof-carrying validator for guard-safe formulas. The work is formal-semantic and does not assert the physical existence of a null-sector object. Version v1.4.2 updates the earlier preprint package by centering the integrated journal manuscript, retaining the boundary-case interpretation note only as an explicitly non-claim appendix, and adding the technical audit and validator-support materials in the archival ZIP package.
Panasenko (Tue,) studied this question.